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On-Line Vacuum Crushing Manifold

Vacuum Crushing Manifold

Click image to enlarge. Disassembled stainless steel crusher, vacuum fittings, magnetic piston and anvil. A sample of olivine from an Iceland picrite before crushing is also included.

Gases trapped within the fluid and melt inclusions contained in minerals and volcanic glasses can be liberated by crushing under vacuum. Our crushing manifold is all-stainless steel construction. One type of sample crusher consists of ¾" O.D. tubing, mounted to the vacuum line through a mini-conflat flange, into which a magnetic piston can be inserted on top of the sample. After evacuating the crusher to low pressure, the magnetic piston is lifted and dropped onto the sample using an external system of three solenoids which are electronically activated in sequence under computer automation. The sample is crushed to a powder over the course of 1-2 minutes by the action of the piston (typically, after crushing >50% of the sample will pass through a 100 μm sieve, depending on the initial amount of sample). A second type of sample crusher consists of modified Swagelok valves containing a replaceable sample bucket and modified stem tip of hardened steel (Burnard-type crushers). This type of crusher has the advantage of very small chamber volume, helping to reduce blank levels. The modified stem tip is forced down onto the sample repeatedly using a pneumatic actuator, crushing the sample to a powder. Extracted sample gases are admitted to the processing line, where reactive gases are removed by a series of SAES getters, and He, Ne and Ar are separated by liquid nitrogen and cryogenic traps prior to mass spec analysis.

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